Bug 734861 - Expose stylesheets, including UA, for a document via inIDOMUtils. r=bz

This patch adds an API to inspector utils that gets all stylesheets associated with a document, including UA sheets.
Bug 875753 -  Color input: Gtk widget. r=karlt
Bug 885289 - Improve context menu behaviour for srcdoc iframes. r=mconley, r=bz
Bug 890690 - Add postDataString property to nsISearchSubmission. r=gavin
Bug 890690 - Support POST searches in about:home. r=gavin
Bug 890690 - Add unit test for POST search engines in about:home. r=gavin